Tubular lamp and holder therefor



Dec. 17, 1946. E. s. MILLS ET AL 2,412,825

TUBULAR LAMP AND HOLDER THEREFIOR Filed June 30, 1944 a W. s 5 m h w mjw ms t Wm A. Wm n m w 1 m Wyw Q E 2 4 w W m U I M M. v hr 0 M I Patented Dec. 17, 1946 TUBULAR LAMP AND HOLDER THEREFOR Erwin S. Mills, Cleveland Heights, and Elton A.v Linsday, Willoughby, Ohio, assignors to General Electric Company, a corporation of New York Application June 30, 1944, Serial No. 542,904

13 Claims.

The present invention relates to tubular lamps and to holders for tubular lamps. It is especially applicable to tubular lamps intended to operate at voltages higher than ordinary house lighting circuit voltage, i. e., 120 volts, or which require for starting a voltage higher than that required by tubular fluorescent lamps now in use and which utilize a hot cathode for starting. Such tubular lamps are termed usually cold cathode lamps. It is to be understood, however, that the invention is not limited thereto necessarily but may be used wherever found applicable.

The object of the invention is to provide 'an improved construction and arrangement of tubular lamp and an improved construction and arrangement of holder therefor, and for a consideration of what we believe to be novel and our invention, attention is directed to the following specification and to the claims appended thereto.

In the drawing, Fig. 1 is a side elevation of a tubular lamp mounted in lamp holders embodying our invention; Fig. 2 is a sectional view through-one of the lamp holders and a partial sectional view through the other with the lamp 'mounted therein; Fig. 3 is a sectional view through one of the lamp holders with the lamp removed from the holder, Fig. 4 is a view of a modification of our lamp holder particularly adapted for mounting two lamps in line, and Fig. 5 is a sectional view of another modified form of lamp holder.

Referring to the drawing, l indicates a tubular lamp mounted in holders 2, there being a holder at each end of the lamp. The holders may be 01' like construction.

Referring particularly to Fig. 3, the lamp comprises a glass tube sealed at its ends and on each end of which is fixed an insulating cap 3. In-

sulating cap 3 may be fixed in position on the sealed end of the glass tube in any suitable way. It is provided with an annular groove 4 which defines a center post 5 and a sleeve or rim 6. On the inner end of cap 3 is a metal plate or disk 1 provided with a plurality of fingers 8 which project through openings in the bottom wall of annular recess 4 and have their outer ends bent inwardly as is indicated at 3 to form lamp contacts. Disk fl is connected with the cathode inside the glass tube. Fixed on the outer end of rim 6is a metal contact ring I. It may be fixed in position in any suitable way. It will be understood that each end of the lamp is provided with a terminal similar to that just described.

The lamp holder comprises a base ll having an axially extending opening l2 which is counterbored to provide a shoulder l3. The outer end of opening I2 is provided with a cover H of insulating material which may be fastened in position by screws or other suitable fastening devices. The base and cover are shaped to provide a recess l5 in which is located a terminal screw l6 threaded into an opening in the end of a contact strip ll positioned in a groove in the inner surface of cover l4. In opening I2 is a contact carrying ring I8 of insulating material which is shaped to seat against shoulder l3 and which has a forwardly projecting sleeve l9 which is counterbored to provide a shoulder against which rests a flange on the end of a tubular contact sleeve 20. Sleeve I9 is spaced from the adjacent wall of the opening in which it is located to form an annular recess 2|. The end of sleeve 20 projects beyond the end of insulating sleeve 9 and is adapted to slide therein. It is biased to a position in which its flanged end is in engagement with the shoulder of insulating sleeve I 3 by means of a spring 22, one end of which engages the flanged end of sleeve and the other. end of which engages a metal eyelet 23 which is attached to disk l8 by a rivet 24 having a contact head 25 located at the bottom of recess 2|. Seated over eyelet 23 is an insulating disk 26 which assists in holding the eyelet in place and serves to form an insulating housing for the eyelet and spring 22. Located between insulating disk 26 and cover I4 is a second spring 21 which at one end is attached to contact strip II, as is indicated at 28, and at the other end is attached to ring l8 by a rivet 2.9 which projects-through ring l8 and is provided with a contact head 30 located in recess 2|. Contact heads 25 and 30 are located in recess 2| diametrically opposite each other. Sleeve 20 is of a diameter to receive post 5 and recess 2| is of a size to receive rim 6.

The lamp holders may be mounted on a support 3| by means of screws 32 which pass through suitable openings in the lamp holders.

In use, the two lamp holders are mounted in spaced relation to each other on a suitable support, being spaced apart a distance, as indicated in Fig. 1, such that the lamp correctly seats between them. To insert a lamp in the lamp holders, one end of the lamp is fitted in the one holder, post 5 being inserted in sleeve 20 and rim 6 being inserted in recess 2|. The lamp is then pushed into the holder against the action of springs 22 and 21. In this connection, it is to be noted that spring 21 is stronger than spring 22 so that spring 22 compresses a predetermined amount before spring 21 yields. When the lamp is inserted, contact fingers 3 first engage the end of contact sleeve 20 after which contact ring "I engages contact heads 25 and 30. The lamp is pushed into the one holder until the other end of the lamp clears the other holder after 'which it is placed in line with the second holder and moved into engagement with it, the lamp being centered axially by the springs.

When in position, the circuit for the lamp is from contact screw 16" through contact strip ll to the contact fingers 9 at the one lamp end,

thence through the lamp to the holder at the other end of the lamp which is similar to that just described and through which the current flows in a similar way.

To remove a. lamp from the circuit, the lamp is moved axially in one direction until it is free of the one lamp holde after which it is moved to an angle to one side of such lamp holder and then removed from the other lamp holder. The clearances between the parts are such as to permit of the lamp being inserted into and removed from a lamp holder when at the slight angle required for it to clear the lamp holder at its other end.

When a lamp is removed from'a lamp holder,

it will be seen that the circuit is opened at three points, namely, at each of the contact heads 25 and 30 and at the contact sleeve, 20; also, in each instance, the circuit is opened in an enclosed place surrounded by insulation. As a result, a circuit of relatively high voltage can be interrupted with a minimum of arcing and with no visible arc, the arc being entirely confined. The live contact head 30 is well removed from the face of the lamp holder, being at the bottom of groove 2|, so that it is not likely to be accidentally contacted by one inserting or removing a lamp. Also it is to be noted that circuit through the lamp is not closed until the lamp is entirely in the holder with its ring l engaging contact heads 30 and 25. This is of importance from a safety standpoint.

Tubular lamps of the type illustrated are well adapted for use in a series circuit, a number of lamps being arranged in series in a line and the circuit being connected to the outer ends of the two end lamps. In such an installation, .a lamp holder as shown in Figs. 1 to 3 may be mounted at the two ends of the string and double lamp holders, such as that shown in Fig: 4, may be located at intermediate points. As shown in Fig. 4, the double lamp holder comprises a base 33 corresponding to base H of Figs. 1 to 3 and a cover .34 corresponding to cover l4 of Figs. 1 to 3. In the base is a recess 35 in which is mounted two oppositely facing structures 36 and 31 each similar to the correspondnig structures shown in Figs. 1 to 3 and adapted to receive lam ends similar to that shown in Figs. 1 to 3. Between the two structures 36 and 31 is a spring 38 which corresponds to the spring 21 of Figs. 1 to 3 and through which the electric circuit is completed from one lamp to the next. No terminal for a line connection is needed. In substance, the Fig. 4 construction duplicates that shown in Figs. 1 to 3, and its use will be obvious from the description already given in connection with Figs. 1 to 3.

In Fig. is shown in sectional view one end of a lamp and a holder of another modification embodying our invention. The tubular glass lamp tube is indicated at 39. It is sealed at each end by a metal end cap 40 to which is attached an electrode 4| located inside the glass envelope 39. Attached to the end of lamp tube 33 is an insulating cap 42 corresponding to cap 3 of Figs. 1 to 3 and provided with walls which define an annular recess 43. At the inner end of recess 43 are contact fingers 44 which are integral with end cap 40, project through openings in cap 42 and have their ends crimped over into a groove in a wall of recess 43 as shown at 45. Fingers 44 form the contact for the lamp end, being electrically connected with the lamp electrode 4|. Fixed on the end of cap 42 is a contact ring 46 corresponding to the contact ring I0 of Figs. 1 to 3. The holder comprises a base 41 which is tubular and is counterbored to provide a shoulder 48 against whichrests a disk 49 of insulating material held by a spring 50 positioned between the disk and an end cover 5| held in place in any suitable manner. The terminal for the holder to which the line circuit is connected is indicated at 52. Integral with disk 49 is a sleeve 53 in which is located a tubular contact sleeve 54 having an inturned edge against which rests an insulating disk 55 held by a spring 56. Connected with contact sleeve 54 is a contact 51 which corresponds to contact 25 of Figs. 1 to 3, and connected with spring 50 is a contact 51 which corresponds to contact 30 of Figs. 1 to 3. Contacts 51 and 51 are adapted to be bridged by contact ring 46 when the lamp end is inserted into the holder to bring its contact fingers 44 into engagement with contact sleeve 54. p

The operation of the arrangement shown in Fig. 5 will be clear from the description already given, it being understood that the two lamp ends are alike and that two holders are suitably mounted in spaced relation to each other a distance apart such that the lamp fits between them. As is the case with springs 22 and 21 of Figs. 1 to 3, spring 50 is stronger than spring 55 so that when a lamp end is inserted in a holder, spring 56 yields first.

In accordance with the provisions of the patent statutes, we have described the principle of op- I eration of our invention, together with the apparatus which we now consider to represent the best embodiment thereof, but We desire to have it understood that the apparatus shown is only illustrative and that the invention may be carried out by other means.

What we claim as new and desire to secure by Letters Patent of the United States is:

1. In combination, a lamp holder comprising a base of insulating material having a recess therein, a spring pressed axially movable insulating member in the recess carrying a contact memher for engaging a lamp contact, spaced contact elements carried by said member, and a tubular lamp having a terminal adapted to be inserted into said recess, said terminal being provided with a, lamp contact and having contact means separate from the lamp contact which connects said spaced contact elements in series electrically.

2. In combination, a lamp holder comprising a base of insulating material having a recess therein, a spring pressed axially movable insulating member in the recess, contacts carried by said member comprising a plurality of spaced peripheral contacts and a central contact, and a tubular lamp having an end adapted to be inserted in said recess and provided with contact means on such end which connects said plurality of spaced contacts and said central contact in series.

3. In combination, a, lamp holder comprising a base of insulating material having a recess therein, a spring pressed axiallymo-vable insulating member in the recess, contacts carried by said member comprising a, plurality of spaced peripheral contacts and a central contact sleeve, and a tubular lamp having an end adapted to be inserted into said recess comprising walls of insulating material which define a sleeve having a contact ring on its end and a recess having a lamp contact at its inner end, said contact ring engaging said spaced contacts and said lamp contact engaging said sleeve to connect the spaced contacts and the contact sleeve in series.

4. The combination with a lamp having an insulating wall at its end which defines a recess and a lamp contact seated within and protected by the wall of the recess, of a lamp holder having a recess into which the lamp end is inserted, a movable member in the lamp holder recess having a plurality of spaced contacts thereon, and means whereby when the lamp end is inserted into the lamp holder recess said spaced contacts are connected in series with each other and with the lamp contact.

5. The combination with a. tubular lamp having an insulating wall at its end which defines a recess and a lamp contact seated within and protected by the wall of the recess, of a lamp holder having a recess therein, a member of insulating material slidable in the recess, spring means biasing said member outwardly, said member being moved by the lamp end when inserted into the lamp holder recess, spaced contact members mounted in the lamp holder recess, and contact means whereby said spaced contacts are connected in series with each other and with said lamp contact when the lamp end is in place in the lamp holder recess. I

6. A lamp holder comprisin walls defining a recess having a shoulder at its forward end, an insulating member slidably mounted in said recess, a spring which biases said member toward said shoulder, spaced contacts carried by said in- .ulating member, one of which is connected to said spring, a conducting member in the lamp holder for connection with lamp terminal and being electrically connected to the other contact, said contacts being adapted to be connected in series electrically when engaged by the conducting end of a lamp inserted into said recess, and terminal means connected with said spring. I

7 A lamp holder comprising walls defining a recess having a shoulder at its forward end, an insulating member slidably mounted in said recess, a spring which biases said member toward said shoulder, spaced contacts carried by said insulating member, one of which is connected to said spring, and a spring pressed sliding terminal sleeve in the lamp holder for connection with a lamp terminal, said sleeve being electrically connected to the other of said contacts, said con tacts being adapted to be connected in series electrically with each other when engaged by the of a lamp, a contact member in said recess for making anelectrical connection with a lamp contact when the lamp terminal engages the recess, spring means biasing the movable member into engagement with the lamp terminal, terminal means carried by said casing and normally opencircuited contact means for electrically connecting the contact member in the recess and said terminal means, said contact means being closedcircuited when engaged by the conducting end of a lamp terminal seated on the insulating member.

10. A lamp holder comprising a casing, an insulating member movably mounted in said casing, said insulating member being provided with a recess for receiving a portion of the end terminal of a lamp, a contact member in said recess for making electrical connection with a lamp contact when the lamp terminal engages the recess, spring means biasing the movable member into engagement with the lamp terminal and normally open-circuited contact means including the contact member in the recess for making electrical connection therewith, said contact means being closed-circuited upon being engaged by the conducting end of a lamp terminal seated on the insulating member.

11. The combination with a lamp having a terminal at one end comprising an insulating wall defining a recess and a lamp contact seated within and protected by said recess, of a lamp holder comprising a casing, an insulating member movably mounted in said casing and being provided with a recess for receiving a portion of the end terminal of a lamp, a contact member in said recess for making an electrical connection with the lamp contact when the lamp terminal engages the recess, spring means biasing the insulating memher into engagement with the lamp terminal and meats for making an electrical connection with said contact member,

12. The combination with a lamp having a terminal at one end comprising an insulating wall defining a recess and a lamp contact seated within and protected by the wall of the recess, of a lamp holder including a casing, an insulating member movably mounted in said casing, a contact member carried by said insulating member and spring means biasing said insulating member into engagement with the lamp terminal so that said contact member is seated in the recess in the lamp terminal to make an electrical connection with the lamp contact.

13. A lamp holder comprising a base having walls defining a recess, terminal means on said base, an insulating member slidably mounted in said recess, a spring biasing said member toward one end of the recess to engage a, lamp terminal, normally open-circuited contact means carried by said insulating member, one part of said contact means being electrically connected to said terminal means, said insulating member being likewise provided with a recess for receiving a portion of the lamp terminal, a spring-pressed movable contact member electrically connected to another part of the contact means and being slidably mounted in the recess of the insulating member for engaging a lamp contact carried by the lamp terminal, said contact means being adapted to be closed-circuited when engaged by the conducting end of a lamp terminal to provide an electrical connection between the springand the contact member when a lamp is inserted in the lamp holder.

ERWIN S. MILLS. ELTON .A. LINSDAY. 

